This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present invention, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
Spray devices, such as spray guns, generally include a number of consumable wear items, which eventually erode due to contact with liquid passing through passages and orifices of the spray device. For example, in paint spraying applications, the liquid exit orifice in spray tips of spray coating guns eventually erodes from contact with the liquid paint at high pressures. Accordingly, the spray tips are typically cast from tungsten carbide to provide wear resistance. Unfortunately, tungsten carbide is relatively expensive and is difficult to cast and machine into the desired geometry, passages, orifices, and so forth.
For example, the process of casting the tungsten carbide into the initial form of the spray tips results in relatively large internal bores for the subsequent machining and processing. Unfortunately, these large internal bores define a large volume, which tends to retain the liquid paint within the spray tip after operation of the spray coating gun. This retention of paint within the spray tip causes the spray coating gun to drip or dribble after operation.
By further example, the hardness of tungsten carbide complicates the process of making the liquid exit orifice in the spray tips. The hardness of tungsten carbide generally precludes the use of some manufacturing techniques, while making it difficult to achieve the desired shape with other manufacturing techniques. Specifically, the hardness of tungsten carbide rapidly wears many manufacturing tools, such as grinding wheels, thereby increasing costs and time associated with replacing the worn tools. Often, the desired shape of the liquid exit orifice cannot be achieved with tungsten carbide, which can lead to reduced performance and undesirable spray characteristics from the spray tip.
For these reasons, a technique is needed to reduce costs, provide wear resistance, reduce undesirable liquid retention and drip, and improve performance of spray tips used in spray devices.